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The small molecule Hesperadin reveals a role for Aurora B in correcting kinetochore-microtubule attachment and in maintaining the spindle assembly checkpoint.

Hauf S, Cole RW, LaTerra S, Zimmer C, Schnapp G, Walter R, Heckel A, van Meel J, Rieder CL, Peters JM - J. Cell Biol. (2003)

Bottom Line: We have identified the small molecule Hesperadin as an inhibitor of chromosome alignment and segregation.Our data imply that Hesperadin causes this phenotype by inhibiting the function of the mitotic kinase Aurora B.Hesperadin also causes cells arrested by taxol or monastrol to enter anaphase within <1 h, whereas cells in nocodazole stay arrested for 3-5 h.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, 1030 Vienna, Austria.

ABSTRACT
The proper segregation of sister chromatids in mitosis depends on bipolar attachment of all chromosomes to the mitotic spindle. We have identified the small molecule Hesperadin as an inhibitor of chromosome alignment and segregation. Our data imply that Hesperadin causes this phenotype by inhibiting the function of the mitotic kinase Aurora B. Mammalian cells treated with Hesperadin enter anaphase in the presence of numerous monooriented chromosomes, many of which may have both sister kinetochores attached to one spindle pole (syntelic attachment). Hesperadin also causes cells arrested by taxol or monastrol to enter anaphase within <1 h, whereas cells in nocodazole stay arrested for 3-5 h. Together, our data suggest that Aurora B is required to generate unattached kinetochores on monooriented chromosomes, which in turn could promote bipolar attachment as well as maintain checkpoint signaling.

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Monoorientation is not corrected in Hesperadin-treated PtK1 cells before anaphase. Live cell imaging of a PtK1 cell treated with 500 nM Hesperadin. Selected stills of a time-lapse movie (Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1), elapsed time from NEB in h:min is shown in the upper left. The approximate positions of the spindle poles are marked by yellow stars. Red dots indicate the centromeric region of two different chromosomes. After NEB (0:00), some chromosomes align to the metaphase plate, but the majority of chromosomes are monooriented (0:17–0:44). Monooriented chromosomes move on the spindle (compare distance between red dots and yellow stars), but they fail to congress. Upon the onset of anaphase, sister chromatids of bioriented chromosomes are pulled to opposite poles (example marked by red arrowheads), whereas both sisters of the monooriented chromosomes move to the same pole.
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fig6: Monoorientation is not corrected in Hesperadin-treated PtK1 cells before anaphase. Live cell imaging of a PtK1 cell treated with 500 nM Hesperadin. Selected stills of a time-lapse movie (Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1), elapsed time from NEB in h:min is shown in the upper left. The approximate positions of the spindle poles are marked by yellow stars. Red dots indicate the centromeric region of two different chromosomes. After NEB (0:00), some chromosomes align to the metaphase plate, but the majority of chromosomes are monooriented (0:17–0:44). Monooriented chromosomes move on the spindle (compare distance between red dots and yellow stars), but they fail to congress. Upon the onset of anaphase, sister chromatids of bioriented chromosomes are pulled to opposite poles (example marked by red arrowheads), whereas both sisters of the monooriented chromosomes move to the same pole.

Mentions: To understand the nature of the observed chromosome segregation defect, we filmed Hesperadin-treated living PtK1 cells by differential interference contrast microscopy. At nuclear envelope breakdown (NEB; Fig. 6 , time 0:00), some chromosomes were usually positioned at an equal distance between the two spindle poles and appeared to rapidly acquire a normal bipolar attachment (Fig. 6, time 0:06). However, other chromosomes that were positioned closer to one of the poles at NEB rapidly acquired a monopolar attachment to that pole. Like monooriented chromosomes in untreated cells (Rieder and Salmon, 1998), these chromosomes exhibited pronounced oscillatory motions toward and away from the pole they were attached to (Fig. 6; see Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1).


The small molecule Hesperadin reveals a role for Aurora B in correcting kinetochore-microtubule attachment and in maintaining the spindle assembly checkpoint.

Hauf S, Cole RW, LaTerra S, Zimmer C, Schnapp G, Walter R, Heckel A, van Meel J, Rieder CL, Peters JM - J. Cell Biol. (2003)

Monoorientation is not corrected in Hesperadin-treated PtK1 cells before anaphase. Live cell imaging of a PtK1 cell treated with 500 nM Hesperadin. Selected stills of a time-lapse movie (Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1), elapsed time from NEB in h:min is shown in the upper left. The approximate positions of the spindle poles are marked by yellow stars. Red dots indicate the centromeric region of two different chromosomes. After NEB (0:00), some chromosomes align to the metaphase plate, but the majority of chromosomes are monooriented (0:17–0:44). Monooriented chromosomes move on the spindle (compare distance between red dots and yellow stars), but they fail to congress. Upon the onset of anaphase, sister chromatids of bioriented chromosomes are pulled to opposite poles (example marked by red arrowheads), whereas both sisters of the monooriented chromosomes move to the same pole.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2172906&req=5

fig6: Monoorientation is not corrected in Hesperadin-treated PtK1 cells before anaphase. Live cell imaging of a PtK1 cell treated with 500 nM Hesperadin. Selected stills of a time-lapse movie (Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1), elapsed time from NEB in h:min is shown in the upper left. The approximate positions of the spindle poles are marked by yellow stars. Red dots indicate the centromeric region of two different chromosomes. After NEB (0:00), some chromosomes align to the metaphase plate, but the majority of chromosomes are monooriented (0:17–0:44). Monooriented chromosomes move on the spindle (compare distance between red dots and yellow stars), but they fail to congress. Upon the onset of anaphase, sister chromatids of bioriented chromosomes are pulled to opposite poles (example marked by red arrowheads), whereas both sisters of the monooriented chromosomes move to the same pole.
Mentions: To understand the nature of the observed chromosome segregation defect, we filmed Hesperadin-treated living PtK1 cells by differential interference contrast microscopy. At nuclear envelope breakdown (NEB; Fig. 6 , time 0:00), some chromosomes were usually positioned at an equal distance between the two spindle poles and appeared to rapidly acquire a normal bipolar attachment (Fig. 6, time 0:06). However, other chromosomes that were positioned closer to one of the poles at NEB rapidly acquired a monopolar attachment to that pole. Like monooriented chromosomes in untreated cells (Rieder and Salmon, 1998), these chromosomes exhibited pronounced oscillatory motions toward and away from the pole they were attached to (Fig. 6; see Video 2, available at http://www.jcb.org/cgi/content/full/jcb.200208092/DC1).

Bottom Line: We have identified the small molecule Hesperadin as an inhibitor of chromosome alignment and segregation.Our data imply that Hesperadin causes this phenotype by inhibiting the function of the mitotic kinase Aurora B.Hesperadin also causes cells arrested by taxol or monastrol to enter anaphase within <1 h, whereas cells in nocodazole stay arrested for 3-5 h.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, 1030 Vienna, Austria.

ABSTRACT
The proper segregation of sister chromatids in mitosis depends on bipolar attachment of all chromosomes to the mitotic spindle. We have identified the small molecule Hesperadin as an inhibitor of chromosome alignment and segregation. Our data imply that Hesperadin causes this phenotype by inhibiting the function of the mitotic kinase Aurora B. Mammalian cells treated with Hesperadin enter anaphase in the presence of numerous monooriented chromosomes, many of which may have both sister kinetochores attached to one spindle pole (syntelic attachment). Hesperadin also causes cells arrested by taxol or monastrol to enter anaphase within <1 h, whereas cells in nocodazole stay arrested for 3-5 h. Together, our data suggest that Aurora B is required to generate unattached kinetochores on monooriented chromosomes, which in turn could promote bipolar attachment as well as maintain checkpoint signaling.

Show MeSH